> The brine came from the ocean.

Sure, and enriched uranium comes from the ground, but that doesn't mean it's safe to dump it back in after the enrichment process!

> So just dilute it back to close to ambient salinity using municipal waste water…

Wouldn't it generally be easier to process that municipal waste water, as is already fairly common?

The analogy would be if you "un-enrich" it. Then it's safe. Or at least no worse than when you took it out of the ground.

> The analogy would be if you "un-enrich" it.

But you're doing that with the same water you're trying to make in the first place!

You could just dilute it using fresh seawater, if you used enough and (maybe) spread it over a wider area. The amount of water people need for drinking is a relative drop in the ocean.

Brine doesn't necessarily behave the way you imagine.

https://en.wikipedia.org/wiki/Brinicle

https://en.wikipedia.org/wiki/Brine_pool

Blue Planet video of a brinicle, content warning for kind of horrifying death of sea creatures: https://www.youtube.com/watch?v=lAupJzH31tc

And a Blue Planet II video of a brine pool, stronger content warning for much more horrifying death: https://www.youtube.com/watch?v=ZwuVpNYrKPY

You can dilute the brine in a facility before disposing.

With fresh water, we’ll get it from desalinization! Hey wait a second…

Sarcasm aside, your comment actually works: you can use the freshwater from desalination!

Just wait for the saltwater to come back around in the sewer.

Globally about 70% of freshwater is used for agriculture so less than a third of it will come back around, if it's exclusively for residential/commercial use you might do better but overall not a strategy that balances out

70% of desalinated water wont ever go to agriculture because its too expensive to use for corn. Only very high value crops need apply.

But, so what? 30% sewage is still a strong dilluant... especially when mixed with more seawater

Im shocked how many people cannot grasp that you can dilute brine's salinity arbitrarily close to seawater's with energetically cheap pumps.

Go on. With what?

Seems like you could just dilute it with seawater at like 100:1 ratio and it would be negligible done offshore. We already dump our shit 5 miles out.

100:1 is overkill and energetically very wasteful. It's a fairly straightforward chemical engineering problem.

gasoline

...sea water. You take 10 units of sea water for every unit processed and you'll get a slight increase in salinity.

A phase diagram tells you exactly how far you need to go.

You know this makes more thermodynamic sense than carbon capture, right?

> Sure, and enriched uranium comes from the ground

Uranium can also come from the ocean water (there is, apparently, quite a lot of it in there, relatively speaking). Japan experimented with the technology in the nineties, but it really was much cheaper to just mine it from the ground, so they abandoned it.

Japan is also barred from doing own enrichment, being a non-nuclear state. Though, there nevertheless is a dormant set of requisite facilities.

You're wrong. Japan does do their own enrichment, 150k SWUs at Rokkasho with plans to bring that up to 500k SWUs a year soon. If they chose to make.bombs instead of fuel, they could make dozens a year.

That's the dormant plant. Rokkasho-mura plant is officially incomplete for decades, doing tests and upgrades without actual production.

If you think otherwise and you're not wrong, and I think you ARE not mistaken since this isn't the first time someone other than myself mentioned it here, that means they're making bombs because we in Japanese public aren't told about it. There has only been just some routine commentaries from local mayors at most.

I think you might be confusing the Rokkasho Reprocessing Plant (not yet operational, intended for plutonium extraction from spent fuel) and the Rokkasho Uranium Enrichment plant, which has been running at 75 tSWU/year (I think that should be kSWU or tSW) since 2023-08-24 https://www.jnfl.co.jp/ja/business/about/uran/daily/enrichme... 112.5 tSWU/year since 2025-06-26 https://www.jnfl.co.jp/ja/business/about/uran/daily/enrichme... and 150 tSWU/year since 2025-11-20 https://www.jnfl.co.jp/ja/business/about/uran/daily/enrichme...

It's a bit weird though that they have a graph of tons of uranium hexafluoride shipped that shows the last shipment in 2018 and nothing since then.

They also have a large stockpile of reactor grade plutonium. Not the best material for bombs, but workable.

It's about 3 parts per billion. Uranium is about $85/pound, so you'd need to be able to completely process/extract about 40 million gallons of saltwater for $85 to break even. The real cost there is orders of magnitude higher. It's one reason the claim about the Earth having vast amounts of uranium is quite disingenuous. The amount of cost efficient accessible uranium is only enough to last ~1 century at current consumption rates. If nuclear energy scaled up significantly, we'd run out in a matter of decades if not less, or we send the price of uranium skyrocketing and the price arguments would need to be significantly adjusted.

Enriched uranium is perfectly safe to dump but it would be stupid to do so. Fission products are nasty but uranium itself is not, comparatively.

Municipal waste water is a much cheaper way to get desalinated water in the first place though.

except for the pharmaceuticals anyway

Hey, it's free viagra, prozac, progesterone and multivitamin supplements, all in a glass.

There’s some fat fish out there, I hope we can get those guys some Ozempic too

Democrats intentionally killing the fishing industry by giving fish free glp1s and cocaine with your tax dollars!

That’s been a solved problem, engineering-wise, for a while.

The advanced treatment stages take care of it. Between UV, ozone, and nanofiltration, etc. we can remove the pharmaceuticals.

Actually the problem is the water comes out too pure out of a well designed water reuse system, to the point where the mineral content can be too low and you need to add some back in.

Cite for it being solved? All the articles I can find have it as ‘active and growing problem with some potential mitigations which are not universally applied’.

All the recycled water systems I’m aware of still have PCC issues and excess ion contamination problems too still.

Admittedly my knowledge was based on work I did in academia, and I now work in transportation, so I suppose it’s possible I’m in error, but I’d be surprised if much survives the RO stage, and isn’t eaten up by the oxidation stage. My understanding was that the water needs to actually get remineralized to protect the distribution system. And that it’s very devoid of pharmaceutical contaminants by that point. I was unaware of this being an issue in real world potable reuse systems. Though, I suppose different jurisdictions may have different standards. My state was pretty strict.